The overall potential yield of biomass energy depends on the land area allocated to producing it. Many of the concerns about expanding the biomass energy industry involve the possibility that new production will occupy land needed for growing food and for conservation. The justification for this concern depends on the quantity and quality of alternative lands (Christopher et al. 2007, Haberl et al. 2007).
An Analysis of The Use of Energy Crops
The physical geographical, especially morphological, endowments in the County of Heves enable primarily its southern parts for crop production that has, in general, a lower share on the national level, compared to the share of population (3%). Among the crops, the predominance of corns is typical with occupying 2/3 of the croplands. From the point of view of energy, the significant share of oil-crops and its increase can be considered as relevant.
The land of oil crops is the most significant from the national aggregate. Its value has been around 6% of the national croplands in years following the Millenium with no remarkable growth experienced. For absolute values, it is indicated that their croplands has been continuously increasing (from 24600 ha to 43250 ha) to a value considered to be very significant within 6 years, but still remaining around the rate of the national value. In case, their yield is examined, an increase of the relevance of these crops in the County of Heves can be witnessed.
Also, the growing of potato and sugar-beet suitable for bioethanol production should be mentioned here; whose share indicates only 1-2 % of the national production lands, however with an increasing tendency. Also, the rate of production has significantly increased with indicating the second highest rate of increase behind the oil crops as compared to 2000 (+50%). This definitely makes an adequate basis for the use for energy purposes.
Summarised, it can be claimed that in the County of Heves, primarily the share of crops suitable for the production of biodiesel and bioethanol has been increasing in recent years, however this share being far behind the magnitude order of corns. In this respect, an energy supply system operated by a mixture of raw materials is recommended.
Table 1: The amount of crops harvested in the County of Heves (tonnes)
It can be claimed that, in the area of the County of Heves, theoretically, winter wheat can be grown for energy purposes even at less favoured areas (however, it is exclusively used for feeding purposes) whereas all other crops, under the present conditions, can be used primarily for food-production (T able 1.).
Of the oil-crops, areas of the rape and sunflower are significant in the micro-region, the endowments favour the field production of these two crops (Table 2.).
Table 2: Areas of the most important oil-crops in the County of Heves
In the case of sunflower, 90% of all crops is utilised as edible oil (Gergely 2009). However, during the production of sunflower, a rather high amount of remnants and by-products are resultant (dead stalk, plates).
Pasture-lands abandoned due to the decreased stocks of sheep and cattle as well as poor-quality ploughlands can be the sites of forestation. According to the joint regulation of the EU an the Hungarian Ministry of Agriculture ad Rural Development, at least once in every 50 year, vexillaries must be planted at croplands. The acidic soils found in the County of Heves mainly facilitate the application of the acerb Lupinus spp. Having it used as a green manure is more advantageous compared to other sweet species as here no damage caused by games should be reckoned with (Gergely 2009).
A programme on the use of energy grass (Miscantus, Szarvasi-1 energy grass) for energy purposes was launched in the Fleischmann Rudolf Research Institute of the Karoly Robert College. This plant is, as a part of an experiment, grown within the county.
Not only the rate of forested areas in the entire county exceeds the national average by 6%, however is far behind of what is potentiated by the ecological potential of the county. Poor-quality plough-lands, steep turfs and pasture-lands that can be abandoned could be involved in the process of renewable energy production from wood by plantation (Table 3).
Table 3: The extent of forestable abandoned pasture-lands and poor-quality croplands for the microregions in the County of Heves
At these areas, within 15-25 years, a timber yield of 84000 bm3, i.e. ca. 35000 tonnes of biomass can be reckoned with (Gergely 2009). This represent a further 518000 GJ of energy, i.e. a significant amount of forestry biomass potential within the County of Heves.
One of the preconditions of utilisation is the appropriate selection of wood species. In case of production for biomass purposes, the plantation of species with a relatively short growth time, as well as the re-introduction of crop rotation of 30 to 40 years, classified as short for slow-propagation species.